Spark-plug.



A. SCHMIDT.

SPARK PLUG.

, APPLICATION FILED JULY 24.1913.

Patented Oct. 10,1916.

' ing drawings.

ALBERT SCHMIDT, or FLINT, mroiimnn, Assmnon TO CHAMPIGN ronrrron' corarm, or FLINT, MICHIGAN, A CGR1OEA'IION or MICHIGAN.

mm m

Specification of Letters Patent.

Pei-tented Get, it), 1916;

Application filed July 24, 1913. Serial No. 780,866,

T 0 all whom it may concern Be it known that I, ALBERT SCHMIDT, citizen of the Republic of Fmnce, residing at Flint, in the county of Genesee and State of Michigan, have invented certain new and useful Improvements in SparlcPlugs, of which the following is a specification, reference being had therein to the accompany- The invention relates to spark plugs, and more particularly to the construction of elec trodes therefor, and the manner Of moun ing the same upon the plug casing.

in the drawings: Figure 1 is a bottom plan view of the plug; Fig. 2 is a cross section thereof; and Fig. 8 is an elevation at rightangles to Fig. 2, showing the construc tion and manner of mounting the ground electrode. v

In 'the construction of spark plugs, it is usual to mount one electrode npoi'i on insu. later core, While the cooperating electrode is grounded upon the metallic casing. This grounded electrode "is frequently formed from a piece or Wire, one end, of which engages an aperture or here in the end of the casing, While the other end is bent-to extend in proximity with the cooperating electrode. One of thegreatest diiiiculties is the dissipation of heat imparted to this electrode by the contact of the with the burning gases. In the present invention 1 have over come this ditticulty by forming the sparking end of the electrode of a lesser cross section than the portion which engages with the outer case, whereby thefhen iis' more rapidly dissipated.

Specifically, A is the metallic casing of the spark plug; 13 the insulator core there for; C the electrode mounted upon said core; and D the cooperating electrode which is grounded on the case. in forming the electrode D, a round piece of Wire is selected,

and is engaged with n l core in the end of the casing in which it issecured by brazing or solder The projecting end of the electrode bent at as ind cated at it, and this ing portion is from its outer end to ment With the case. '11-- ticel plane and the electrode is so directed as to lie adjacent to the insulated electrode ing through said core, end at c C, as show" in Fig, l. I preferably section into the portion which extends in the bore in the case, and from the latter through the brazed or soldered portion into the main case A, This prevents the over heeting of the outer end of the electrode,

and is also :1 construction which can be easily manufactured at small cost.

Vrhat I claim as my invention is:

1. A, spark ping, comprising acasing, an IHSUlZLlJOI core therein, an electrode projecting through said core, and e cooperating electrode, having a shank portion engaging said casing, and a laterellyextendinn portion of substantially semi-circular ore ;s-section', the cross-sectional area er said laterally eXten-ding portion gradually increasing from the outer end to the shank portion, and an edge of said semi-circular portion being edjecent to the electrode projecting through the core. l

h 2. A spark plug, comprising e, casing, an insulator core therein, an electro proiectp atlilg electrode, having a. shank portion engaging said casing, andzi laterally-extending portion tapering from the shank portion to its free end and provided with a longitudinallyextending edge portion ad acent to the electrode projecting through the core.

3. In a spark plug the combination with a casing, of in electrode having a shank portion engaging said casing and laterallyextending portion tapering in a plane passing through said shank portion and said laterally extending portion from the shank portion to the free end, a side edge of the interadepted to WV. G. LA ROCK. 

